Identifying diode, LED, resistor and capacitor — NEET & JEE Questions

Question 1 · difficulty L1 · recall

A resistor is commonly identified by

• A. a transparent light-emitting lens only
• B. a polarity stripe marking a cathode on every resistor
• C. colour bands or printed resistance markings
• D. two unequal capacitor plates visible externally

Question 2 · difficulty L1 · understanding

A typical LED can often be identified by

• A. having no p-n junction
• B. being a nonpolar fixed resistor
• C. showing identical behaviour in both directions
• D. a light-emitting package and polarity-sensitive leads

Question 3 · difficulty L2 · understanding

An ordinary semiconductor diode is a

• A. two-terminal polarity-sensitive p-n junction device
• B. nonpolar resistor
• C. three-terminal transistor only
• D. mechanical switch

Question 4 · difficulty L2 · application

A capacitor is primarily used to

• A. produce radioactive decay
• B. store electric charge and energy in an electric field
• C. measure magnetic declination
• D. act as a perfect DC conductor indefinitely

Question 5 · difficulty L2 · understanding

Which component is designed primarily to allow current much more readily in one direction than the other?

• A. Diode
• B. Resistor
• C. Capacitor
• D. Ideal connecting wire

Question 6 · difficulty L3 · application

Using a multimeter diode-test mode, a healthy silicon diode typically shows

• A. the same low resistance in both directions
• B. zero voltage in both directions always
• C. a forward drop in one direction and open/high reading in the reverse direction
• D. light emission necessarily even for any diode

Question 7 · difficulty L3 · application

A resistor measured with an ohmmeter should ideally give

• A. opposite signs of resistance
• B. a forward diode drop only one way
• C. infinite resistance one way and zero the other
• D. approximately the same resistance when leads are reversed

Question 8 · difficulty L3 · application

A two-terminal component emits visible light when forward biased. It is most likely a

• A. light-emitting diode
• B. fixed resistor
• C. capacitor
• D. fuse only

Question 9 · difficulty L3 · application

A component is marked with a capacitance value in microfarads and is used to store electric charge temporarily. It is a

• A. capacitor
• B. resistor
• C. LED
• D. rectifier diode only

Question 10 · difficulty L4 · analysis

A polar electrolytic capacitor should be connected with

• A. correct polarity according to its markings
• B. either polarity at any voltage without concern
• C. its two leads shorted
• D. the positive lead always to ground